Absolute photoionization cross sections of the Ba ground state in the autoionization region: II. 221-209 nm

Absolute photoionization cross sections of Ba in the autoionization region of 209-221 nm have been measured with a bandwidth of 0.0014 nm. The measure d cross sections are compared with those obtained from R-matrix calculation s combined with multichannel quantum defect theory (MQDT) techniques. The v ariations of the experimental lineshape parameters for the 5d(D-2(3/2))np[1 /2] and 5d(D-2(5/2))np[3/2] series are analysed with empirical three-channe l MQDT models. From the calculation of partial density of stares in 6pns ch annels, the perturber of the 5d(D-2(3/2))np[1/2] series is confirmed to be the 6p7s P-3(1) level and that of the 5d(D-2(5/2))np[3/2] series is identif ied as the 6D7s P-1(1) level.